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PubMed1990

Individualized adaptation of clothes for impaired persons. A comparison of two groups with and without experience of adapted clothes.

Impaired persons often have difficulties in obtaining suitable clothing. Questionnaires on this subject were sent to a consecutive series of impaired persons. Group 1 (n = 50) had received adapted clothes and group 2 (n = 81) had not. Questionnaire A (both groups) contained general questions on clothes and questionnaire B (Group 1) contained questions on adapted clothes. The result of the study shows a significant difference (p less than 0.01) between the need for adapted clothing in group 1 and group 2. No significant difference was found between the groups regarding the reason for obtaining and using adapted clothes. It was difficult for 94% in group 1 and 85% in group 2 to obtain clothes which were suitable for the individual's impairment and which made their daily activities easier. In group 1 the adapted garments were of most value when dressing and undressing (86%). They also reduced the time needed, by 31% for the individual, by 43% for a helper; and by 62% when going to the toilet. The adapted garments were considered smarter and more comfortable by 64%. Eighteen per cent considered that wearing them had increased their self-confidence.

Activities of Daily Living↗

PubMed1978

Olfactory self- and cross-adaptation: effects of time of adaptation on perceived odor intensity.

The time-course of self- and cross-adaptation of the olfactory system was investigated for two constant concentrations of three odorous substances. The substances (hydrogen sulfide, dimethyl disulfide, and pyridine) were matched, in a pilot experiment, with regard to perceived odor intensity. The time of adaptation was controlled by the number of inhalations (1-10). A two-step scaling method, involving cross-modality matching and numerical scaling of the matching continuum, was used for measuring perceived odor intensity during adaptation. The results show that the time-course function for self-adaptation seems to be an exponential function for two of the substances (H2S, DMDS), while for the third (pyridine) the form of the function is less distinct. Cross-adaptation between substances was found for the high concentrations, while for the low concentrations, hydrogen sulfide and dimethyl disulfide gave rise to pronounced cross-facilitation. The latter effect increased with time of adaptation.

Adaptation, Physiological↗

PubMed1993

[The biphasic nature of the phenomenon of structural adaptational stabilization during the long-term adaptation of the body to stress].

During long-term (28 days) adaptation of the body to stress, the structural adaptational stabilization phenomenon (SASP) has a marked two-phase pattern: (1) SASP formation during nearly 14 days when protein transcription in heat shock was activated, hsp 70 was substantially accumulated and cardiac resistance to reperfusion damage drastically increased and (2) SASP reduction occurring despite continuous adaptation. By day 28 myocardial adaptation showed only two hsp 70 isoforms of the five revealed on day 14 of stress adaptation. Correspondingly, by day 28, the anticontractural effect of adaptation and its capacity of retaining the high contraction amplitude turned out to vanish in reperfusion. Moreover, ventricular fibrillation and ventricular tachycardia were observed in the control animal hearts during reperfusion, whereas these arrhythmias were seen only in 25 and 50% cases on days 14 and 28, respectively.

Adaptation, Physiological↗

PubMed1990

Laboratory properties of cold-adapted influenza B live vaccine strains developed in the US and USSR, and their B/Ann Arbor/1/86 cold-adapted reassortant vaccine candidates.

The adaptation of two influenza B strains (B/Leningrad/14/55 and B/Ann Arbor/1/66) to replication at 25 degrees C is described. Comparison of the two viruses indicates that both also exhibit temperature sensitive phenotypes, although that of the virus B/Leningrad/14/55 is less pronounced. When inoculated into ferrets both viruses replicate well in the trachea, but only the B/Leningrad/14/55 cold-adapted virus replicates in the lungs. This virus exhibited a moderate level of attenuation in the animals, in contrast to the B/Ann Arbor/1/66 cold-adapted virus, which was fully attenuated. Reassortant viruses deriving the surface antigens of the contemporary wild type virus B/Ann Arbor/1/86 and most or all of their other genes, from one or other cold-adapted parent, were virtually indistinguishable from their respective cold-adapted parents. The B/Leningrad/14/55 reassortant was slightly more attenuated than its cold-adapted parent in ferrets. These studies extend knowledge of the properties of viruses used to prepare experimental live influenza B human vaccines.

Animals↗

PubMed2004

Improving adaptive display with temporally adaptive rendering.

Making computer imagery more responsive and realistic is one of the most basic goals of graphics researchers, and adaptive display is one of the primary means for achieving it. While previous displays have achieved a spatial adaptivity, our research focuses on achieving temporal adaptivity--sampling some regions not only more densely, but also more often. We use closed loop feedback to guide sampling to image regions that change significantly over space or time. Adaptive reconstruction emphasizes older samples in static settings, resulting in sharper images; and new samples in dynamic settings, resulting in images that may be blurry but are up-to-date. In terms of peak signal-to-noise ratio, this prototype produces much better image streams than nonadaptive renderers with the same simulated sampling rates. This new display also offers new opportunities for adapting to user state, allowing adaptive response both where and when it is needed. Our prototype system already responds interactively to changes in the user's viewpoint, it might also respond to any of a number of other indications of user state, including eye tracking, repeatedly manipulated objects, and biometrics.

Data Display↗

PubMed1990

Time course of adaptation and recovery from adaptation in the cat auditory-nerve neurophonic.

The auditory-nerve neurophonic (ANN) reflects the ensemble response of phase-locked firing in single auditory-nerve fibers to sustained signals. Consequently, neural response properties such as adaptation and recovery from adaptation can be observed. In this study, ANN responses to 800-Hz, 100-ms tones presented at 10-30-dB SL were recorded using bipolar platinum-iridium electrodes placed on the auditory nerve of the cat. The cat ANN adaptation properties were determined and fit to the equation: A(tp) = Yre(-tp/tau Ar) + Yse(-tp/tau As) + Ass. The rapid time constant of adaptation (tau Ar) was invariant across stimulus level, with a mean value of 4.8 (+/- 2.1) ms. The short-term time constant (tau As) decreased approximately 21 ms for each 10-dB increase in probe amplitude. The mean tau As was 116 ms at 10 dB SL, 83.2 ms at 20 dB SL, and 73.5 ms at 30 dB SL. The ANN recovery from adaptation data was analyzed and fit to the equation: A(delta t) = Amax - Yre(-delta t/tau Rr) - Yse(-delta t/tau Rs). Here, tau Rr, the rapid time constant of recovery, and tau Rs, the short-term time constant, were independent of masker intensity in the studied range, with values of 16.2(+/- 9.8) and 125(+/- 50.1) ms, respectively. The results of this study indicate that ANN time constants are comparable to those measured for single units and that the adaptation behavior of phase-locked and nonphase-locked activity appears to be similar.

Animals↗

PubMed1975

Cyclical effects of triiodothyronine on blood-free fatty acid and glucose concentrations in warm-adapted and cold-adapted rats.

Effects of triiodothyronine (T3) (100 mug/100 g, sc) on blood-free fatty acid (FFA) and glucose concentrations were investigated in warm- and cold-adapted rats. Blood specimens were obtained from the tail locally anesthetized with lidocaine. In warm-adapted rats FFA rose 3 to 6 hr after administration of T3, but returned to the pre-injection level 12 hr later. Thereafter, blood FFA level showed a repeated cyclical rise and fall every 12 hr for up to 60 hr, while blood glucose level did not increase until 12 hr later and this level was maintained for up to 36 hr. After that time it also showed a repeated rise and fall every 12 hr for up to 60 hr. Both FFA and glucose levels returned to the initial values after 72 hr. Changes induced by T3 in blood levels of these metabolites were reciprocal. In cold-adapted rats the patterns of responses to T3 were essentially the same as those observed in warm-adapted ones, except that T3 provoked a simultaneous rise in blood glucose as well as FFA 6 hr after injection, although an extent of FFA increment was less than in warm-adapted rats. Reserpine pre-treatment caused a considerable reduction in the FFA mobilizing action of T3. The FFA and glucose mobilizing action of T3 was also observed at dosages of 25 and 6.25 mug/100 g, although to lesser extent. These results indicated for the first time the cyclical action of T3 on blood FFA and glucose concentrations, and a changed sensitivity to T3 in cold-adapted animals.

Acclimatization↗

PubMed1975

In vivo lipolytic effect of glucagon in warm-adapted and cold-adapted rats.

In vivo effect of glucagon on blood-free fatty acid (FFA) concentration was investigated in rats adapted to 25 degree C and to 5 degree C. Intraperitoneal injection of glucagon in 100 or 25 mug/100 g body weight doses was followed by a triphasic response in blood FFA concentration: an immediate and marked rise at 5 min, a secondary depression at 60 min and a final rise at 120 to 240 min after the injectionss. For the 12.5 and 6.25 mug/100 g body weight injections, an initial increment was significantly lowered and no elevation at 240 min was observed. Concomitant elevations of blood glucose concentration were shown 5 min after glucagon injection of 100, 25, 12.5, and 6.25 mug/100 g body weight doses and their extents were not significantly different each other between these doses. However, rise in blood glucose level at 60 min was not seen at the 12.5 and 6.25 mug/100 g body weight doses. Blood lactate concentrations did not show any significant variations by the injections of glucagon. In fasting rats, glucagon at the 100 mug/100 g body weight dose caused similar increase in blood FFA as that in fed ones. In fed cold-adapted rats at 5 degree C glucagon at the dose of 100 mug/100 g body weight brought about similar effects in elevation of blood FFA level and its time-course as those in fed rats adapted to 25 degree C. However, under fasting condition cold-adapted animals exhibited greater increment in blood FFA level at 5 min than those adapted to 25 degree C, while an elevation of blood FFA at 240 min was not observed in the former animals. These results indicate for the first time an in vivo lipolytic action of glucagon in rats and further suggest an enhanced sensitivity to lipolytic action of glucagon in cold adaptation.

Acclimatization↗

PubMed2002

Toll-like receptor 4 and Toll-IL-1 receptor domain-containing adapter protein (TIRAP)/myeloid differentiation protein 88 adapter-like (Mal) contribute to maximal IL-6 expression in macrophages.

Previous studies have shown that engagement of Toll-like receptors (TLR) 2 and 4 can induce macrophages to express a variety of proinflammatory cytokines. We have recently demonstrated that TLR2 agonists poorly induce a subset of TLR4-inducible proinflammatory genes (e.g., inducible protein (IP)-10, inducible NO synthase (iNOS), monocyte chemoattractant protein-5, IL-12p40), due in part to differential activation of IFN-beta production and phosphorylation of the transcription factor STAT1. TLR4, but not TLR2, agonists can induce IFN-beta expression via a mechanism that requires the adapter protein Toll-IL-1R domain-containing adapter protein (TIRAP)/myeloid differentiation protein 88 (MyD88) adapter-like (Mal), but not the adapter protein MyD88. Thus, the failure of TLR2 agonists to induce STAT1-dependent genes results, in part, from their failure to induce the expression of IFN-beta. In this study, we show that IL-6 expression is also preferentially induced by activation of TLR4. TLR4-dependent induction of IL-6 expression did require Toll-IL-1R domain-containing adapter protein (TIRAP)/MyD88 adapter-like (Mal), but unlike iNOS and IP-10, it did not require the expression of IFN-beta. Although exogenous IFN-beta and IFN-gamma could synergize with TLR2 agonists to restore high levels of iNOS expression and NO production, these IFNs could not synergize with TLR2 agonists to induce high levels of IL-6. Similarly, neutralizing anti-IFN Abs could block iNOS gene expression in LPS-stimulated murine macrophages, whereas these Abs had little effect on IL-6 gene expression in these cells. Together, these studies demonstrate that IL-6, like iNOS and IP-10, is differentially expressed in macrophages stimulated via TLR2 vs TLR4, although these differences appear to arise from distinct signaling mechanisms.

Adaptor Proteins, Signal Transducing↗

PubMed1992

Changes in sensitivity of the dark-adapted eye during concurrent light adaptation of the other eye.

Thresholds for detection of light by a dark-adapted test eye were measured while the other, non-test eye was either similarly dark adapted or while it was exposed to an intense red adapting field. An interocular effect that depends on the retinal location of the test was found: compared to the threshold during binocular dark adaptation, sensitivity decreased during contralateral light adaptation when the test was presented to the foveola and up to 4 deg above it; but sensitivity increased when the test was between 7 and 12 deg, showing a reversal at 5 deg.

Adaptation, Ocular↗

PubMed2000

A physiological model of dark-adapted and light-adapted photoreceptors of the honeybee.

A physiological model of dark-adapted and light-adapted photoreceptors in the honeybee worker (Apis mellifera) has been developed. Almost all of the electrophysiological components of photoreceptors known up to date, e.g. the phototransduction cascade, the ion channels of the membrane, phototransduction gain and optical adaptation mechanisms, are adequately described by simple biophysical and biochemical models. The connections of these components were tried out in synthetic simulations for best fits of simulated to intracellularly recorded membrane potentials. Although the parameters of the best model were determined exclusively for the measured membrane potentials of dark-adapted photoreceptors, the model also accurately describes the light-adapted photoreceptor membrane potentials. Furthermore, the model correctly predicts the time-courses of measured photoreceptor responses with respect to squared-modulated flicker lights up to 200 Hz. This clearly demonstrates that the presented photoreceptor model is indeed a physiologically adequate description of the essential components of the phototransduction and the electrical membrane processes in the photoreceptors of the honeybee worker.

Adaptation, Physiological↗

PubMed2004

Background light adaptation of the retinal neuronal adaptive system. II. Dynamic effects.

The dynamic effects of continuous exposure to light on the neuronal adaptive system of the retina, as indicated by the oscillatory response (OPs) of the electroretinogram (ERG) were studied in the albino rat. Digitally filtered OPs and the a- and b-waves of the corneal ERG were simultaneously recorded in dark adaptation, during continuous light adaptation to four levels of background light (BGL) changing in steps of two log units from 1.43 x 10(-6) cd/m2, referred to as 'low and high scotopic, low and high mesopic' levels. Exposed to 'high scotopic' BGL the total oscillatory response (SOP) significantly enhanced within the first minute, whereas the amplitudes of the a- and b-waves were unaffected. In 'low mesopic' BGL the SOP increased within the first minute, whereas the a- and b-waves significantly decreased. 'High mesopic' BGL instantaneously and profoundly reduced both the SOP and the slow potentials. The individual OPs changed in amplitudes mainly within the first minute of BGL. In general, the earlier OPs (O1 and O2) reacted more to the two 'scotopic' BGL levels, whereas the later OPs (O3 and 04) were more affected by the relatively brighter two 'mesopic' conditions. In conclusion, the rapid increase of the OPs within the first minute of 'high scotopic' and 'low mesopic' BGL exposure may represent a rudimentary light adaptational effect in the rod-dominated rat retina. These findings also suggest that the neuronal adaptive mechanism of the retina seems to be a robust system, probably attaining preservation of visual abilities in the rat on exposure to light.

Adaptation, Ocular↗

PubMed1975

Effect of activation and adaptation on the sensitivity of slowly adapting cutaneous mechanoreceptors.

The effect of adaptation on the sensitivity of type I and type II cutaneous mechanoreceptors was evaluated with test stimuli applied before, during and after a persistent indentation (offset) of the skin. It was found that the offset initially lowered the threshold to both high (100-200 Hz) and low (1-20 Hz) frequency sinusoidal stimuli, as compared with the preoffset condition. This lowered threshold increased for both stimuli as adaptation progressed. When adaptation was nearly complete, there was an appreciable residual reduction of threshold, as compared with preoffset values, for the low frequency stimuli but not for high frequency stimuli. For a time after the offset was removed, the threshold was increased above preoffset levels for both stimuli. Suprathreshold ramp displacements superimposed on an offset caused higher maximal frequencies and a larger change in frequency than before the offset was applied. This difference often was considerable (20-40 impulses/sec) even though the discharge produced by the offset had adapted to only 2-4 impulses/sec above the preoffset level. Shortly after removal of the offset, the ramp responses typically were less than before the offset was applied. Thus, these receptors are not "reset" to the preoffset condition by adaptation nor is their sensitivity reduced. On the contrary, they respond more vigorously to superimposed stimuli except for near threshold displacements that are brief and rapid.

Adaptation, Physiological↗

PubMed1995

Adaptation mechanisms in spatial vision--II. Flash thresholds and background adaptation.

To examine how the mechanisms of light adaptation affect spatial pattern vision, contrast detection thresholds were measured for sinusoidal (increment-Gabor) probes on flashed backgrounds in the presence of steady adapting backgrounds. The thresholds for all spatial frequencies (1-12 c/deg), flashed-background intensities (dark to 4 log td) and adapting-background intensities (dark to 4 log td) were adequately described by a simple model consisting of a compressive nonlinearity (a modified Naka-Rushton function), a subtractive adaptation factor, and a multiplicative adaptation factor. For all five subjects the compressive nonlinearity was found to vary systematically with spatial frequency; for all but one subject, the subtractive and multiplicative factors were found to be relatively constant.

Adaptation, Ocular↗

PubMed1995

Adaptive determinism during salt-adaptation in Sorghum bicolr.

During adaptation to salinity, plants of Sorghum bicolor showed malformations affecting the leaves in development (DPL). At the end of the adaptation process, the plants were regrouped according to their pattern of DPL response. The distribution of the plant population in different patterns depended on environmental conditions. However, a positive relationship between the frequency of a pattern and its rate of development has been found. Similarly, a negative relation between the frequency of a pattern and the rate of senescence for the same pattern has been observed. The results reveal the existence of an orientation of the plant response towards the patterns with highest developmental rate and lowest rate of senescence. This property is defined as 'adaptive determinism'. Results indicate that the NaCl acts as a trigger for adaptation to a whole range of environmental perturbations. This suggests that adaptation to salinity is not a pre-programed response of the plants, and may be related to learning processes occurring in animals.

Adaptation, Physiological↗

PubMed2006

What is adapted in face adaptation? The neural representations of expression in the human visual system.

The neural representation of facial expression within the human visual system is not well defined. Using an adaptation paradigm, we examined aftereffects on expression perception produced by various stimuli. Adapting to a face, which was used to create morphs between two expressions, substantially biased expression perception within the morphed faces away from the adapting expression. This adaptation was not based on low-level image properties, as a different image of the same person displaying that expression produced equally robust aftereffects. Smaller but significant aftereffects were generated by images of different individuals, irrespective of gender. Non-face visual, auditory, or verbal representations of emotion did not generate significant aftereffects. These results suggest that adaptation affects at least two neural representations of expression: one specific to the individual (not the image), and one that represents expression across different facial identities. The identity-independent aftereffect suggests the existence of a 'visual semantic' for facial expression in the human visual system.

Adaptation, Physiological↗

PubMed2006

Selectivity of neuronal adaptation does not match response selectivity: a single-cell study of the FMRI adaptation paradigm.

fMRI-based adaptation paradigms (fMR-A) have been used to infer neuronal stimulus selectivities in humans. Inferring neuronal selectivities from fMR-A, however, requires an understanding of the relationship between the stimulus selectivity of neuronal adaptation and responses. We studied this relationship by recording single cells in macaque inferior temporal (IT) cortex, an area that shows fMRI adaptation. Repetition of identical object images reduced the responsiveness of single IT neurons. Presentation of an image to which the neuron was unresponsive did not alter the response to a subsequent image that activated the neuron. Successive presentation of two different images to which the neuron responded similarly produced adaptation, but less so than the repeated presentation of an image. The neuronal adaptation at the single-cell level showed a greater degree of stimulus selectivity than the responses. This complicates the interpretation of fMR-A paradigms when inferring neuronal selectivity.

Adaptation, Physiological↗

PubMed1994

A comparison of the second harmonic generation from light-adapted, dark-adapted, blue, and acid purple membrane.

The second order nonlinear polarizability and dipole moment changes upon light excitation of light-adapted bacteriorhodopsin (BR), dark-adapted BR, blue membrane, and acid purple membrane have been measured by second harmonic generation. Our results indicate that the dipole moment changes of the retinal chromophore, delta mu, are very sensitive to both the chromophore structure and protein/chromophore interactions. Delta mu of light-adapted BR is larger than that of dark-adapted BR. The acid-induced formation of the blue membrane results in an increase in the delta mu value, and formation of acid purple membrane, resulting from further reduction of pH to 0, returns the delta mu to that of light-adapted BR. The implications of these findings are discussed.

Adaptation, Physiological↗